JP5222982B2 - A connecting member used for connecting a steel pipe and a bolt of a floor bundle or turnbuckle, and a manufacturing method thereof - Google Patents

Description

  The present invention relates to a floor bundle or turnbuckle, a coupling member that constitutes a coupling portion between the steel pipe and the bolt, a method for manufacturing the coupling member, a coupling portion using the coupling member, and a floor including the coupling portion. Concerning bundles and turnbuckles.

A floor bundle or turnbuckle capable of supporting a form against an axial stress is often used as a building material for a building.
When the floor bundle and the turnbuckle main body are constructed of steel pipes, the joints between the steel pipes and bolts are conventionally formed with female threads on the inner surfaces of the ends of the steel pipes, and the bolts are screwed onto the female threads. It is configured so that they can be combined.

  Alternatively, the nut end face is brought into contact with the open end face of the steel pipe, and the joint portion with the bolt is formed by direct welding.

No. 7-4263

  If an internal thread structure is formed directly on the inner wall surface of a steel pipe, the thickness of the steel pipe will be reduced by the formed internal thread structure, so an extra thick steel pipe had to be used in anticipation of the thinning. .

  Moreover, in order to form the female thread on the inner surface of the end of the steel pipe, it takes time for the forming process and requires advanced technology and equipment. It was the cause that pushed up the product price of certain floor bundles and turnbuckles.

  In addition, the joint formed by the method of welding the nut end face to the opening end face of the steel pipe requires advanced technology to completely weld the nut and the steel pipe, which takes time and improves the welding finish accuracy. There was a possibility that a variation occurred and a defective product having an incomplete welded part was generated in mass production. If the welded part is incomplete, when stress is applied to the floor bundle or turnbuckle, the joint may be damaged even if the load is smaller than the assumed force.

  Also, when it is necessary to perform the welding work with the shaft of the nut and the shaft of the steel pipe aligned, if the nut is pressed against the end surface of the steel pipe and welded, the shaft of the steel pipe and the shaft of the nut are connected due to burr on the end surface of the steel pipe It is difficult to make sure that the nuts coincide with each other, and the nut shaft may be inclined by the welding operation.

  Thus, the present invention has been conceived in order to solve the above problems. The first invention of the present application newly considered a coupling member to be attached to a steel pipe in order to screw a bolt axially into a steel pipe used for a main body of a floor bundle or turnbuckle. In this coupling member, a nut member having a female screw hole that is formed on a prismatic surface and penetrates in the axial direction between both end surfaces is located between the female screw hole and the outer periphery and is concentric with the female screw hole. The thickness of the nut member is maintained at the inner part from the circular boundary line, and the outer part from the circular boundary line is compressed and deformed in both axial directions by the press pressure. A bulge portion is formed which has a step from the surface and becomes lower and bulges outward in the radial direction. The bulge portion is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulge portion and concentric with the female screw hole. A radially outer peripheral edge portion of the bulging portion is cut off along a circular cutting line.

  Other invention of this application is a manufacturing method of the above-mentioned coupling member. The coupling member is located between the female screw hole and the outer periphery of a nut member having a female screw hole that is formed on a prismatic surface and penetrates in the axial direction between both end surfaces, and is concentric with the female screw hole. With a certain circular boundary line as a boundary, the inner part from the circular boundary line maintains the thickness of the nut member, and the outer part from the circular boundary line is compressed and deformed in both axial directions by the press pressure, whereby the both ends Forming a bulging portion that is lowered with a step from the surface and bulges radially outward, is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion, and is concentric with the female screw hole A radial outer peripheral edge portion of the bulging portion is cut off along a circular cutting line.

  Still another invention of the present application is a method of manufacturing a joint for axially screwing a steel pipe and a bolt used for a floor bundle or turnbuckle, wherein the outer periphery is formed in a prismatic surface, and between the both end surfaces. A nut member having a female screw hole penetrating in the axial direction at a boundary between the female screw hole and the outer periphery, and a circular boundary line concentric with the female screw hole as a boundary, The thickness of the nut member is maintained, and the portion outside the circular boundary line is compressed and deformed in both axial directions by the press pressure, and thereby lowers from the both end surfaces with respective steps and radially outward. A bulging portion is formed that bulges and is radially larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion and along a circular cutting line that is concentric with the female screw hole. By cutting off the outer peripheral edge to form a collar A steel pipe is formed by forming a connecting member, inserting the connecting member into the steel pipe end from the open end of the steel pipe so that the axis of the female screw hole coincides with the axis of the steel pipe, and applying a press pressure to the end of the steel pipe. Is deformed toward the inside in the radial direction, and the inner surface of the end portion of the steel pipe is plastically deformed along the outer surface of the flange portion of the coupling member.

  Here, in order to plastically deform the inner surface of the steel pipe end along the outer surface of the flange of the coupling member, the press pressure applied to the end of the steel pipe applies pressure to the steel pipe on the surface orthogonal to the axis of the steel pipe. Is preferably deformed so as to approach the inner diameter direction, whereby the steel pipe is deformed inward in the radial direction.

  The joint according to the present invention, which is obtained by inserting the coupling member into the steel pipe and joining it by applying a press pressure to the steel pipe, is easier to form than the prior art in which a female thread is directly formed on the inner surface of the end of the steel pipe. In addition, reliable and strong joining can be realized as compared with the conventional technique in which the nut end face is welded to the steel pipe end face.

  Further, the position of the circular boundary line is determined so that the interval width between the female screw hole and the circular boundary line is 60% or more and 98% or less with respect to the shortest length between the female screw hole and the outer periphery of the nut member. Is good.

  This is because if the circular boundary line is set at such a position and the compression deformation process is performed, a concave portion can be suitably formed on the outer peripheral surface of the bulging portion obtained by cutting off the outer peripheral edge portion along the circular cutting line. It is.

  When the outer part of the circular boundary line is compressed and deformed in both axial directions by the pressing pressure with the circular boundary line as the boundary, the outer part of the nut member flows in the axial direction and expands outward in the radial direction. The bulging part is formed by taking out. At this time, when the circular boundary line is set at the above position, the thin width portion (the side portion of the end face) of the portion outside the circular boundary line of the nut member flows from both axial directions and bulges in the outer diameter direction. On the other hand, the compressive deformation is completed without the protruding portion being in close contact, and the thick width portion (corner portion of the end face) of the portion outside the circular boundary line of the nut member flows from both axial directions and is pushed out in the outer diameter direction. A concave portion is formed on the outer peripheral surface of the thin portion by completing the compressive deformation in a state where the bulging portion swelled up in a lump is extended in a lump shape.

  Further, the circular cutting line is larger than the shortest outer diameter of the nut member and smaller than the shortest outer diameter of the bulging portion, that is, the outer diameter at the position closest to the female screw hole in the outer peripheral edge of the bulging portion. By being concentric with the shaft of the female screw hole, the outer peripheral edge of the bulging part can be cut off over the entire circumference, and the outer peripheral edge of the collar part formed by cutting off the outer peripheral edge part of the bulging part is completely Can be formed into a perfect circle. As a result, when a coupling member is inserted into the steel pipe and a pressing portion is applied to form a coupling portion, the joining of the flange portion and the steel pipe deformed along the flange portion becomes uniform over the entire circumference. Thus, a uniform joining force between the steel pipe and the coupling member can be realized.

  Furthermore, when manufacturing the coupling part, when the coupling member is inserted into the end of the steel pipe and press pressure is applied, the inner wall of the steel pipe is deformed into the concave part by forming a concave part in the collar part, The steel pipe and the coupling member can be firmly engaged in the recess. Thereby, a coupling member can be firmly joined with respect to a steel pipe. Moreover, the said recessed part is formed by the polygonal number of corners, and the joining force with respect to the steel pipe of a coupling member can be improved further.

  In addition, as described above, the circular cutting line is a circle that is larger than the shortest outer diameter of the nut member and smaller than the shortest outer diameter of the bulging portion and is concentric with the shaft of the female screw hole. If the periphery is formed into a perfect circle, when the coupling member is inserted into the steel pipe and press pressure is applied to form the coupling portion, the amount of deformation of the inner wall of the steel pipe into the recess can be increased. The meshing effect with the steel pipe can be further strengthened.

  Since the circular cutting line is larger than the shortest outer diameter of the nut member, the concave portion does not completely disappear even by cutting off the outer peripheral edge of the bulging portion, and the concave portion is not formed on the outer peripheral surface of the flange portion of the coupling member. Therefore, the effect of meshing with the steel pipe in the concave portion as described above can be obtained with certainty.

  Further, by arranging the plurality of recesses spaced apart at equal intervals, the joining of the coupling member and the steel pipe can be made uniform with respect to the circumferential direction, and the steel pipe and the coupling member are homogeneous. Can achieve a strong bonding force.

  In addition, the position of the circular boundary line is determined so that the interval width between the female screw hole and the circular boundary line is 60% or more and 98% or less with respect to the shortest length between the female screw hole and the outer periphery of the nut member. However, it is preferable to determine the position of the circular boundary line so that it is more preferably 80% or more and 96% or less.

  When the interval width between the female screw hole and the circular boundary line is 60% or less with respect to the shortest length between the female screw hole and the outer periphery of the nut member, the outer portion of the nut member is compressed and deformed. The necessary press pressure is unnecessarily increased. And the efficiency of the press pressure required in order to obtain the compression deformation required to be 80% or more is good.

  On the other hand, if the interval width between the female screw hole and the circular boundary line is larger than 98% with respect to the shortest length between the female screw hole and the outer periphery of the nut member, the outer portion of the nut member is thinner than the circular boundary line. This is because when the width portion is compressed and deformed, the width portion does not sufficiently bulge in the outer diameter direction, and the bulging portion is not sufficiently formed only in that portion, or the periphery of the concave portion is missing. If it is 98% or less, the bulging portion is sufficiently formed over the entire circumference.

  The nut member is preferably a hexagonal nut having an outer periphery formed as a hexagonal column surface and having a female screw hole penetrating in the axial direction between both end surfaces. Hex nuts are sold at a very low price in the market. By using this, it is possible to reduce the manufacturing cost of coupling members, and to reduce the manufacturing cost of floor bundles and turnbuckles with strong joints. It is because it can be suppressed to.

  Further, the floor bundle according to the present invention is provided with the coupling member. That is, a circular boundary in which an outer periphery is formed in a prismatic surface and a nut member having a female screw hole penetrating in the axial direction between both end faces is located between the female screw hole and the outer periphery and is concentric with the female screw hole With the line as a boundary, the inner part of the circular boundary line retains the thickness of the nut member, and the outer part of the circular boundary line is compressed and deformed in both axial directions by the press pressure. A bulging portion that has a step and becomes lower and bulges radially outward, is larger than the shortest outer diameter of the nut member, is smaller than the outer diameter of the bulging portion, and is a concentric circle with the female screw hole A linking member is formed by cutting off a radially outer peripheral edge portion of the bulging portion along a cutting line to form a flange portion, and the shaft of the female screw hole coincides with the axis of the steel pipe. Insert from the open end of the steel pipe into the end of the steel pipe The steel pipe is deformed inward in the radial direction by applying a press pressure to the end of the steel pipe, and a coupling portion is provided which is plastically deformed along the outer surface of the flange portion of the coupling member. To do.

  Furthermore, the turnbuckle according to the present invention is equipped with the coupling member. That is, a circular boundary in which an outer periphery is formed in a prismatic surface and a nut member having a female screw hole penetrating in the axial direction between both end faces is located between the female screw hole and the outer periphery and is concentric with the female screw hole With the line as a boundary, the inner part of the circular boundary line retains the thickness of the nut member, and the outer part of the circular boundary line is compressed and deformed in both axial directions by the press pressure. A bulging portion that has a step and becomes lower and bulges radially outward, is larger than the shortest outer diameter of the nut member, is smaller than the outer diameter of the bulging portion, and is a concentric circle with the female screw hole A linking member is formed by cutting off a radially outer peripheral edge portion of the bulging portion along a cutting line to form a flange portion, and the shaft of the female screw hole coincides with the axis of the steel pipe. Insert from the open end of the steel pipe into the end of the steel pipe The steel pipe is deformed inward in the radial direction by applying a press pressure to the end of the steel pipe, and a coupling portion is provided which is plastically deformed along the outer surface of the flange portion of the coupling member. To do.

  According to the invention of the present application, it is possible to manufacture a coupling member that can be joined to a steel pipe evenly and firmly in the circumferential direction.

  According to the present invention, it is possible to manufacture a coupling member that is surely joined to a steel pipe regardless of welding.

  According to the invention of the present application, it is possible to easily form a concave portion on the outer peripheral surface of the bulging portion only by pressing pressure, and it is possible to manufacture a coupling member that enables strong bonding that can achieve an engagement effect with a steel pipe. .

  According to this invention, since a hexagon nut can be used for a nut member, a coupling member, a floor bundle, and a turnbuckle can be manufactured easily and inexpensively.

  According to the present invention, since the coupling member is arranged along the inner surface of the steel pipe, it is easy to match the axis of the coupling member and the axis of the steel pipe, and it is possible to easily and reliably manufacture the coupling portion where the axis centers coincide.

  According to the present invention, since it is not necessary to use welding for joining with the steel pipe, the floor bundle and the turnbuckle can be manufactured at low cost.

4 is a perspective view of a nut member 2. FIG. It is a top view of the nut member 2. FIG. 4 is a side view of the nut member 2. FIG. 7 is a perspective view of an intermediate body 7. FIG. 2 is a perspective view of a coupling member 1. FIG. FIG. 5 is a half cross-sectional view showing a state in which a nut member 2 is installed in the press device 101. FIG. 5 is a half cross-sectional view showing a state in which an intermediate body 7 is formed by compressing a nut member 2. FIG. 6 is a half cross-sectional view showing a state where the intermediate body 7 is taken out from the press apparatus 101. FIG. 6 is a half cross-sectional view showing a state in which the intermediate body 7 is installed in the press device 210. FIG. 5 is a half cross-sectional view showing a state in which the intermediate member 7 is sheared to form the coupling member 1. FIG. 5 is a half cross-sectional view showing a state in which the coupling member 1 is taken out from the press device 201. It is the longitudinal cross-sectional view which showed a mode that the coupling member 1 and the steel pipe 21 were installed in the press apparatus 301. FIG. It is the longitudinal cross-sectional view which cut | disconnected the steel pipe 21 and the coupling member 1 in which the process which applies a press pressure was completed, and the connection part 22 was formed in the surface at right angles with respect to the front. It is the bottom view of the steel pipe 21 and the coupling member 1 in which the process of applying press pressure was completed and the coupling | bond part 22 was formed. 3 is a longitudinal sectional view of a floor bundle 24. FIG. 3 is a longitudinal sectional view of a turnbuckle 33. FIG.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the nut member 2 used for manufacturing the coupling member 1 is formed by forming an opening 5 in the end surface 4 with an internally threaded hole 3 penetrating in the axial direction. Particularly preferred as the nut member 2 is a hexagonal nut material having a hexagonal column with an outer peripheral surface that is easily available at a low cost. Therefore, in this embodiment, the nut member 2 in FIG. 1 is represented by a hexagonal nut material.

  2 and 3 are a plan view and a side view of the nut member 2, respectively.

  Next, a method for manufacturing the coupling member 1 from the nut member 2 will be described.

  First, as shown in FIG. 6, the nut member 2 is installed in a press device 101 including a reverse presser 102, a die 103, a punch 104, a base 105, and a spring 106. In FIG. 6, the left side of the alternate long and short dash line is a front view, and the right side of the alternate long and short dash line is a vertical cross-sectional view. A positioning projection 107 is formed at the center of the reverse presser 102, and the intermediate body 7 can be installed at the center of the reverse presser 102 and the presser 103 by inserting the female screw hole 3 into the positioning projection 107.

  Here, the outline of the press device 101 will be described. The reverse presser 102 is incorporated in the die 103. In the reverse presser 102, the upper surface of the shoulder portion 108 of the reverse presser 102 is locked by the lower surface of the flange portion 109 of the die 103 while continuing to receive the upward pressing force by the spring 106 installed between the bottom surface and the base 105. Then, the mounting surface 110 of the reverse presser 102 is stationary with the upper surface of the die 103 being located on the substantially same plane. The die 103 is fixed on the base 105.

  Further, the punching hole 108 of the die 103 and the punching hole 109 of the punch 104 are concentric circles of the female screw hole 3, and are circular boundary lines that are slightly smaller than an inscribed circle whose diameter is the shortest outer diameter of the nut member 2. 6 (a circle indicated by a two-dot chain line in FIGS. 1 and 2). The position of the circular boundary line 6 is indicated by a two-dot chain line in FIG. In the present embodiment, as shown in FIG. 2, the circular boundary line has a space width b between the female screw hole 3 and the circular boundary line 6 such that the shortest length a between the female screw hole 3 and the outer periphery of the nut member 2. In contrast, it was 90%.

  After the nut member 2 is installed, the punch 104 is moved downward to perform press pressure processing for compression of the nut member 2. After the lower end of the punch 104 is in contact with the upper end surface 4 of the nut member 2, when the punch 104 is further pushed down, the inner portion of the circular boundary line 6 of the nut member 2 holds the thickness of the nut member 2 together with the reverse presser 102. While descending. On the other hand, a portion of the nut member 2 outside the circular boundary line 6 is press-pressed by the punch 104 and the die 103, and is compressed and deformed from both the upper and lower directions in the axial direction.

  In FIG. 7, the state of the intermediate body 7 and the press apparatus 101 obtained by completing the press pressure processing of the nut member 2 is shown. 8 and 4 show a front view and a perspective view of the intermediate body 7 taken out from the press apparatus 101, respectively. 7 and 8, the left side of the alternate long and short dash line shows a front view, and the right side of the alternate long and short dash line shows a longitudinal sectional view. In the press pressure processing, a portion of the nut member 2 that is inside the circular boundary line 6 maintains the thickness of the nut member 2 before processing, and is formed in a cylindrical coupling member center portion having an end surface 9. 8 is formed. Further, when the coupling member center portion 8 is formed, a step surface 10 is also formed on the circular boundary line 6 by the press pressure processing, and the step surfaces 4a and 4b are lowered from the both end surfaces 4. On the other hand, a portion of the nut member 2 that is outside the circular boundary line 6 is compressed and deformed to form a bulging portion 11 that bulges outward in the radial direction of the female screw hole 3.

Here, the step 10a shown in FIG. 7 is preferably 35% or more and 45% or less with respect to the nut member thickness 2a, and the step 10a + step 10b is 50% or more and 80% with respect to the nut member thickness 2a. The following is preferable. If the level difference 10a is less than 35% with respect to the nut member thickness 2a, it is difficult to match the end faces of the coupling member 1 and the steel pipe because the level difference between the flange 18 and the coupling member center 8 is small. Further, if the level difference 10a + the level difference 10b is larger than 80 with respect to the nut member thickness 2a, the thickness of the flange 18 is not sufficient, and the bonding strength against the stress in the axial direction of the coupling portion may be insufficient. . By satisfying the above conditions, the thickness of the flange portion 18 can be sufficiently taken, and the heights of the steps 10a and 10b can be taken sufficiently, so that sufficient bonding strength against the axial stress is provided. A joint can be formed. In this embodiment, the step 10a is 40% of the nut member thickness 2a, and the step 10b is 30% of the nut member thickness 2a.
In addition, when forming a coupling part, it is preferable that the end surface 4 on the step 10 a side of the coupling member 1 is configured to coincide with the end surface of the steel pipe 21. This is because it is easy to exert a force against the stress in the axial direction.

  As shown in FIG. 4, in the present embodiment, the bulging portion 11 has six wide portions (wide bulging portion 12) and six narrow portions (narrow bulging portion 13) alternately formed. It is formed in a star-shaped outer shape in plan view. A thick concave portion 15 is formed on the outer peripheral surface 14 of the bulging portion along the circumferential direction at a position corresponding to the narrow bulging portion 13.

  The thick concave portion 15 is a short meridian portion of the nut member 2 (that is, a central portion of a hexagonal deformation) and compressed outside the circular boundary line 6 by the die 103 and the punch 104 in the press pressure processing. The female thread portion 3 is formed by being raised outward in the radial direction.

  Next, the intermediate body 7 is installed in a press apparatus 201 including a die 202 and a punch 203 as shown in FIG. A positioning projection 204 is formed at the center of the die 202, and the intermediate body 7 can be installed at the center of the die 202 by inserting the female screw hole 3 into the positioning projection 204. In FIG. 9, the left side of the dashed line in the drawing shows a front view, and the right side of the dashed line in the drawing shows a longitudinal sectional view.

  The punch 203 is larger than the shortest outer diameter of the nut member 2 and smaller than the outer diameter of the bulging portion, and is the same as the circular cutting line 16 (circle shown by a two-dot chain line shown in FIG. 4) concentric with the female screw hole. A punching hole 205 having a diameter is provided, and the intermediate body 7 installed on the die 202 is sheared into a circular shape from above in the axial direction. As shown in FIG. 10, the sheared intermediate body 7 has a radially outer peripheral edge portion 17 of the bulging portion 11 cut into a circular shape, and a flange portion 18 is formed in a state where the stepped surface 10 is left. Is formed. In FIG. 10, the left side of the alternate long and short dash line is a front view, and the right side of the alternate long and short dash line is a vertical cross-sectional view.

  11 and 5 show a front view and a perspective view of the coupling member 1 taken out from the press device 201, respectively. In FIG. 11, the left side of the alternate long and short dash line in the drawing shows a front view, and the right side of the dash and dotted line in the drawing shows a vertical sectional view.

  On the outer peripheral surface 19 of the flange portion 18, a plurality of concave portions 20 left by cutting the radially outer peripheral edge portion of the bulging portion 11 are formed along the circumferential direction. The recesses 20 are formed at equal intervals in the circumferential direction, and the number of the recesses 20 formed in this embodiment is six corresponding to the thick recesses 15.

  Moreover, the recessed part 20 formed in the collar part 18 is expanded and formed toward radial direction outward from the coupling member center part 8, as shown in sectional drawing of FIG. In the press pressure processing, the portion of the nut member 2 outside the circular boundary line 6 was compressed and deformed, and the outer edge portion of the coupling member central portion 8 was raised while bulging outward in the radial direction. It is the characteristic shape by the said press pressure processing formed by this.

  Further, as shown in the front view portion of FIG. 11 and FIG. 5, the width in the vertical direction of the left and right central portion of the recess 20 is formed wider than the width in the vertical direction of the left and right end portions of the recess 20. An independent recess 20 is formed for each hexagonal side. This is because the portion of the nut member 2 that is outside the circular boundary 6 in the hexagonal sides and corners of the nut member 2 whose end face shape is formed in a hexagonal shape in the press pressure processing. This is because the side portion is thin and the corner portion is thick.

  The connecting member 1 obtained through the shearing process is combined with a steel pipe to form a connecting portion. A process for forming the coupling portion will be described below.

  As shown in FIG. 12, the press device 301 includes a die 303 having a holding protrusion 302, a press pressure die 304, a holding die 305, and a base 306. The die 303 and the holding die 305 are springs 307 and 308, respectively. It is connected to the base 306 via The press die 304 is fixed on the base 306.

  The holding protrusion 302 protrudes from the side surface of the die 303 in the horizontal direction, and is a cylindrical protrusion having an outer diameter slightly smaller than the inner diameter of the female screw hole 3 of the coupling member 1. A groove die 309 is formed on the inner peripheral surface of the press pressure die 304 to plastically deform the steel pipe 21 along the outer surface of the flange portion 18 and apply a press pressure. The holding mold 305 is formed with a cylindrical groove mold 310 having a shape matched to the peripheral surface of the steel pipe 21 in order to stably hold the steel pipe 21 in a state in which the steel pipe 21 is kept horizontal at the time of installation.

  First, the coupling member 1 is fitted into the holding projection 302 and fixed in a state where the end surface 9 of the coupling member central portion 8 is in contact with the side surface of the die 303, and then the steel pipe 21 is installed and the steel pipe 21 is opened from the opening of the steel pipe 21. The coupling member 1 is inserted into the end. Then, the outer surface is placed on the holding mold 305 in a state where the end surface of the steel pipe 21 is in contact with the side surface of the die 303 so as to be kept horizontal. Thereby, it can be set as the state which aligned the end surface of the coupling member 1 and the steel pipe 21 on the same plane.

  After the installation of the coupling member 1 and the steel pipe 21 is completed, the press die 304 is pressed against the steel pipe 21 from above vertically with respect to the axis of the steel pipe 21 so that the steel pipe 21 is directed radially inward along the flange 18. Apply sufficient pressure to deform. At this time, since the die 303 and the holding mold 305 also move in accordance with the movement of the steel pipe 21 vertically downward with respect to the shaft, the press pressure can be applied while keeping the steel pipe 21 and the shaft of the coupling member 1 horizontal. it can.

  After the process of applying the press pressure to the steel pipe 21 is completed, the press die 304 is pushed up vertically again with respect to the axis, and the steel pipe 21 in which the coupling portion 22 is formed is taken out. FIG. 13 shows a longitudinal sectional view of the steel pipe 21 in which the coupling portion 22 is formed, and FIG. 14 shows a bottom view of the steel pipe 21 in which the coupling portion 22 is formed.

  As shown in FIG. 13, the steel pipe 21 to which the pressing pressure is applied by the pressing die 304 is in close contact with the outer surface of the flange portion 18, and the coupling portion 22 is easily formed without using welding. Yes. The shafts of the steel pipe 21 and the coupling member 1 are also joined together.

  Furthermore, when the inner wall of the steel pipe 21 to which the pressing pressure is applied is pushed into the recess 20, the engagement portion 23 that can engage the steel pipe 21 and the coupling member 1 with the recess 20 can be formed. By forming the meshing portion 20, the coupling member 1 can be more firmly joined to the steel pipe 21. In addition, since the six recesses 20 are provided on the peripheral surface of the flange portion 18, the meshing portions 20 can also be formed at six locations along the peripheral surface of the steel pipe 21, thereby the steel pipe 21 of the coupling member 1. The bonding force with respect to can be kept uniform in the circumferential direction.

  In FIG. 15, the longitudinal cross-sectional view of the floor bundle 24 which provided the coupling member 1 which concerns on this invention in the coupling | bond part 22 is shown.

  In the floor bundle 24, the coupling portion 22 is formed in a body portion 25 formed based on the steel pipe 21, and a bolt shaft 26 is coupled to the coupling member 1. A leg portion 27 is fixed to a lower end portion of the bolt shaft 26 by a nut 28, and the bolt shaft 26 and the body portion 25 are also fixed by a nut 30 through a washer 29. In addition, a top plate 27 is provided at the upper end portion of the body portion 25 to place and support a large pull on the upper surface. The top plate 31 is provided with a cylindrical inner fitting portion 32 integrally formed downward from the top plate 31, and the inner fitting portion 32 and the upper end portion of the trunk portion 25 are pressed against each other. It is joined by being added.

  In FIG. 16, the longitudinal cross-sectional view of the turnbuckle 33 which provided the coupling member 1 which concerns on this invention in the coupling | bond part 22 is shown.

  In the turnbuckle 33, the coupling portion 22 is formed at both ends of a body portion 34 formed based on the steel pipe 21, and hooks 35 and 32 are coupled to the coupling members 1 and 1. A bolt screw is formed at the base end portion of the hook 35. The hook 35 is fixed by a nut 37 via a body portion 34 and a washer 36. The turnbuckle 33 can be used as a joint by hooking a wire or the like to the hooks 35 and 32.

DESCRIPTION OF SYMBOLS 1 Coupling member 2 Nut member 3 Female screw hole 4 End surface 6 Circular boundary line 7 Intermediate body 8 Coupling member center part 10 Step surface 11 Swelling part 15 Thick recessed part 16 Circular cutting line 18 Gutter part 20 Recessed part 21 Steel pipe 22 Coupling part 23 Meshing part

Claims (5)

In order to screw a bolt in the axial direction to a steel pipe used for a floor bundle or a turnbuckle, a manufacturing method of a connecting member to be attached to the steel pipe,
The nut member having an outer periphery formed in a prismatic surface and having a female screw hole penetrating in the axial direction between both end surfaces,
With a circular boundary line located between the female screw hole and the outer periphery being concentric with the female screw hole,
The portion inside the circular boundary line holds the thickness of the nut member,
The outer portion of the circular boundary line is compressed and deformed from both axial directions by press pressure, thereby forming a bulging portion that has a step difference from the both end faces and bulges radially outward.
A radially outer peripheral edge of the bulging portion is cut off along a circular cutting line that is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion and concentric with the female screw hole. A method for manufacturing a coupling member. In order to screw the bolt in the axial direction to the steel pipe used for the floor bundle and turnbuckle, it is a coupling member attached to the steel pipe,
A nut member whose outer periphery is formed in a prismatic surface and has a female screw hole penetrating in the axial direction between both end surfaces,
With a circular boundary line located between the female screw hole and the outer periphery being concentric with the female screw hole,
The inner part of the circular boundary line retains the thickness of the nut member,
The outer portion of the circular boundary line is compressed and deformed from both axial directions by the press pressure, thereby forming a bulging portion that has a step difference from the both end faces and bulges radially outward.
The radially outer peripheral edge of the bulging portion is cut off along a circular cutting line that is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion and concentric with the female screw hole. A characteristic coupling member. A method of manufacturing a joint for axially screwing a steel pipe and a bolt used for a floor bundle or turnbuckle,
The nut member having an outer periphery formed in a prismatic surface and having a female screw hole penetrating in the axial direction between both end surfaces,
With a circular boundary line located between the female screw hole and the outer periphery and concentric with the female screw hole as a boundary,
The portion inside the circular boundary line holds the thickness of the nut member,
The outer portion of the circular boundary line is compressed and deformed from both axial directions by press pressure, thereby forming a bulging portion that has a step difference from the both end faces and bulges radially outward.
A flange is formed by cutting off the radially outer peripheral edge of the bulging portion along a circular cutting line that is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion and concentric with the female screw hole. To form a coupling member,
The coupling member is inserted from the open end of the steel pipe so that the axis of the female screw hole coincides with the axis of the steel pipe,
By applying press pressure to the end of the steel pipe, the steel pipe is deformed radially inward,
A method for manufacturing a coupling portion, comprising plastically deforming an inner surface of an end portion of a steel pipe along an outer surface of a flange portion of the coupling member. A floor bundle in which a bolt is screwed in an axial direction to a joint provided at an end of a steel pipe,
A nut member whose outer periphery is formed in a prismatic surface and has a female screw hole penetrating in the axial direction between both end surfaces,
With a circular boundary line located between the female screw hole and the outer periphery and concentric with the female screw hole as a boundary,
The inner part of the circular boundary line retains the thickness of the nut member,
The outer portion of the circular boundary line is compressed and deformed from both axial directions by the press pressure, thereby forming a bulging portion that has a step difference from the both end faces and bulges radially outward.
A radially outer peripheral edge portion of the bulging portion is cut off along a circular cutting line that is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion and is concentric with the female screw hole. A coupling member formed,
The coupling member is inserted from the open end of the steel pipe so that the axis of the female screw hole coincides with the axis of the steel pipe,
By applying press pressure to the end of the steel pipe, the steel pipe is deformed radially inward,
A floor bundle comprising a connecting portion formed by plastically deforming an inner surface of an end portion of a steel pipe along an outer surface of a flange portion of a connecting member. A turnbuckle in which a bolt is axially screwed to a joint provided at an end of a steel pipe,
A nut member whose outer periphery is formed in a prismatic surface and has a female screw hole penetrating in the axial direction between both end surfaces,
With a circular boundary line located between the female screw hole and the outer periphery and concentric with the female screw hole as a boundary,
The inner part of the circular boundary line retains the thickness of the nut member,
The outer portion of the circular boundary line is compressed and deformed from both axial directions by the press pressure, thereby forming a bulging portion that has a step difference from the both end faces and bulges radially outward.
A radially outer peripheral edge portion of the bulging portion is cut off along a circular cutting line that is larger than the shortest outer diameter of the nut member and smaller than the outer diameter of the bulging portion and is concentric with the female screw hole. A coupling member formed,
The coupling member is inserted from the open end of the steel pipe so that the axis of the female screw hole coincides with the axis of the steel pipe,
By applying press pressure to the end of the steel pipe, the steel pipe is deformed radially inward,
A turnbuckle comprising a coupling portion formed by plastic deformation of an inner surface of a steel pipe end portion along an outer surface of a flange portion of a coupling member.

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